1. Field of the Invention
The present invention relates to an inkjet recording medium and a manufacturing method thereof.
2. Description of the Related Art
A wide variety of information-processing systems have been developed as the information-technology industry has made rapid strides forward, and recording methods and apparatus suitable for the information-processing systems have also been developed and put to practical use.
Of these recording methods, an inkjet recording method has come to be widely used not only in offices but also at home for at-home recording because it has the advantages that recording can be performed on various kinds of recording materials and the hardware (apparatus) required is relatively low priced, compact, and outstandingly quiet.
In addition, with the improvement in resolution of images printed by recent inkjet printers, it has become possible to obtain recorded matter of photograph-like high quality, and with this evolution of the hardware (apparatus), various kinds of media for inkjet recording have been developed.
Properties required of recording sheets for inkjet recording generally include (1) a property of drying quickly (having a high ink absorption speed), (2) a property of ensuring ink dots of a correct and uniform diameter (being free of bleeding), (3) a property of ensuring good graininess, (4) a property of ensuring ink dots of high roundness, (5) a property of ensuring high color densities, (6) a property of ensuring high color saturation (no dullness), (7) a property of ensuring high resistance to water, light and ozone in the printed portion, (8) a property of having a high degree of whiteness in the background portion, (9) a property of having good storability (a property of causing neither yellow coloration even over long-term storage nor bleeding of images by long-term storage (bleeding with age)), (10) a property of having high resistance to deformation and good dimensional stability (having sufficiently limited curling), and (11) a property of ensuring smooth running in apparatus.
When recording sheets are used as glazed photo paper for the purpose of obtaining photograph-like high-quality recorded matter, they are further required to have glossiness, surface smoothness and texture resembling that of photographic printing paper for silver-salt photographs in addition to the properties recited above.
For the purpose of improving these properties, inkjet recording media having porous structures in their respective ink-receiving layers have been developed and put to practical use in recent years. Such inkjet recording media can have excellent ink receptivity (quick-dry properties) and high glossiness owing to their porous structures.
For example, inkjet recording media having, on a substrate, an ink-receiving layer containing fine particles of an inorganic pigment and a water-soluble resin, and having high porosity, have been proposed (see, for example, JP-A Nos. 10-119423 and 10-217601).
Owing to their makeup, these recording media, in particular, an inkjet recording medium provided with an ink-receiving layer having a porous structure using silica as fine particles of inorganic pigment, have high ink absorbency and ink receptivity high enough to form images of high resolution, and can exhibit high glossiness.
On the other hand, among ingredients incorporated into an ink-receiving layer, cationic polymers are known as a component for improvements in prevention of bleeding (see, for example, JP-A Nos. 2006-321176 and 2006-248017).